Talk:Selected ion flow tube

This template is no longer used.

Instrumentation

The SIFT apparatus

In the SIFT apparatus the ions are created in an ion source which is external to the flow tube. The ions are then extracted from the ion source, selected according to their mass-to-charge ratio using a quadrupole mass filter and injected into a flowing carrier gas (usually helium at a pressure of 0.5 Torr) via a small orifice ( ~1 mm diameter).

The carrier gas is inhibited from entering the quadrupole mass filter chamber by injecting it into the flow tube through a Venturi-type inlet at near-supersonic velocity in a direction away from the orifice. In this way a swarm of a single ion species thermalised at the same temperature as the carrier gas are convected along the flow tube ( ~1 m long), sampled by a downstream pinhole orifice, mass analysed and counted by a differentially-pumped quadrupole mass spectrometer system.

}}

moved from front page --K. Murray 21:16, 5 May 2005 (CDT)